1   /* Copyright 2002-2025 CS GROUP
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3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
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8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
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16   */
17  package org.orekit.orbits;
18  
19  import org.orekit.bodies.CR3BPSystem;
20  import org.orekit.utils.PVCoordinates;
21  
22  /** Class calculating different parameters of a Lyapunov Orbit.
23   * @author Vincent Mouraux
24   * @since 10.2
25   */
26  public class LyapunovOrbit extends LibrationOrbit {
27  
28      /**
29       * Simple Constructor.
30       * <p>
31       * This constructor can be used if the user wants to use a first guess from
32       * any other sources or if he has the initial conditions of a well defined Lyapunov Orbit.
33       * In that case, it is assumed that the user knows the
34       * characteristics of the Lyapunov Orbit leading to this first guess/point. Also, the
35       * orbital period of this Lyapunov Orbit has to be specified for further
36       * computation.
37       * </p>
38       * @param syst CR3BP System considered
39       * @param pv PVCoordinates of the initial point or of the first guess
40       * @param orbitalPeriod Normalized orbital period linked to the given Lyapunov Orbit first guess
41       */
42      public LyapunovOrbit(final CR3BPSystem syst,
43                           final PVCoordinates pv, final double orbitalPeriod) {
44          super(syst, pv, orbitalPeriod);
45      }
46  
47      /**
48       * Simple Constructor.
49       * <p>
50       * Standard constructor, the first guess will be computed with both start
51       * time and phase equal to zero.
52       * </p>
53       * @param richardson third-Order Richardson Expansion
54       * @param ay y-axis amplitude of the required Lyapunov Orbit, meters
55       */
56      public LyapunovOrbit(final RichardsonExpansion richardson,
57                           final double ay) {
58          super(richardson.getCr3bpSystem(),
59                richardson.computeLyapunovFirstGuess(ay, 0.0, 0.0),
60                richardson.getLyapunovOrbitalPeriod(ay));
61      }
62  
63      /** {@inheritDoc} */
64      @Override
65      protected PVCoordinates applyCorrectionOnPV(final CR3BPDifferentialCorrection diff) {
66          return diff.compute(LibrationOrbitType.LYAPUNOV);
67      }
68  
69  }
70